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101.
Magda P��l Vikt��ria Kov��cs Gyula Vida Gabriella Szalai Tibor Janda 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(1):35-47
Investigations were made on four wheat (Triticum aestivum L.) lines under greenhouse conditions, in order to reveal the role of stress-protective materials, namely salicylic acid, polyamines and antioxidant enzymes in the level of tolerance to powdery mildew infection caused by Blumeria graminis (DC.) Speer f.sp. tritici ém. Marchal. The four lines showed different levels of tolerance, assessed on the Saari-Prescott scoring scale: TC26 and TC33 proved to be susceptible and TC9 and TC19 resistant. In most of the lines, infection caused changes in the activities of antioxidant enzymes, especially in the case of guaiacol peroxidase. Four peroxidase isoenzymes, which responded differently to powdery mildew infection could be detected by gel electrophoresis. Infection had only a slight effect on the levels of salicylic acid (free and bound forms) in inoculated plants; while the levels of polyamines, especially spermidine and spermine increased after infection. Correlation analysis was also performed to examine how close a relationship exists between the parameters investigated. It was concluded that salicylic acid, polyamines and antioxidant enzymes have an important role in plant responses and defence mechanisms during this biotic stress and that in some cases there were significant relationships between them. However the levels of these compounds either initially or after pathogen inoculation, could not explain the degree of tolerance to powdery mildew in the four wheat lines investigated. 相似文献
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103.
This study was aimed at characterizing the potential differences in gene expression in piglets inoculated with Porcine circovirus type 2 (PCV2), the essential causative agent of postweaning multisystemic wasting syndrome. Seven-day-old caesarean-derived, colostrum-deprived piglets were distributed into two groups: control (n = 8) and pigs inoculated with 105.2 TCID50 of the Burgos PCV2 isolate (n = 16). One control and three inoculated pigs were necropsied on days 1, 2, 5, and 8 post-infection (p.i.). The remaining pigs (four of each group) were sequentially bled on days 0, 7, 14, 21, and 29 p.i. (necropsy). Total RNA from the mediastinal lymph node (MLN) and lysed whole blood (LWB) samples were hybridized to Affymetrix Porcine GeneChip®. Forty-three probes were differentially expressed (DE) in MLN samples (FDR < 0.1, fold change > 2) and were distributed into three clusters: globally down-regulated genes, and up-regulated genes at early (first week p.i.) and late (day 29 p.i.) stages of infection. In LWB samples, maximal differences were observed at day 7 p.i., with 54 probes DE between control and inoculated pigs. Main Gene Ontology biological processes assigned to up-regulated genes were related to the immune response. Six common genes were found in both types of samples, all of which belonged to the interferon signaling antiviral effector pathway. Down-regulated genes were mainly related to cell adhesion and migration in MLN, and cellular organization and biogenesis in LWB. Microarray results were validated by quantitative real-time PCR. This study provides, for the first time, the characterization of the early and late molecular events taking place in response to a subclinical PCV2 infection. 相似文献
104.
Sara Moreno Bel��n Alvarez Teresa Poderoso Concepci��n Revilla Angel Ezquerra Fernando Alonso Javier Dominguez 《Veterinary research》2010,41(5)
Monocyte subsets have been shown to differ in the pattern of chemokine receptor expression and their migratory properties, both in human and mouse. Previously we have characterized in the swine several monocyte subpopulations, based on the expression of CD163, Tük4 and SLA-II, which share features with the populations described in human and mouse. Here, we have analysed the expression of different chemokine receptors in the CD163−Tük4+SLA-II− and CD163+Tük4−SLA-II+ populations of porcine monocytes. CD163+Tük4−SLA-II+ monocytes expressed higher CX3CR1 but lower CCR2 and CXCR4 mRNA levels than CD163−Tük4+SLA-II− monocytes. Moreover, porcine CCL2 binding on Tük4+SLA-II− but not on Tük4−SLA-II+ cells was detected by using a CCL2-green fluorescence protein (pCCL2-GFP) fusion protein. Finally, flow cytometric analyses of monocytes recovered after chemotaxis assays show a clear increase in the proportion of Tük4+SLA-II− cells in the fraction migrating toward CCL2, consistent with the polarized CCR2 expression in this monocyte population. The pattern of expression of these chemokine receptors reinforces the similarities of these porcine subsets with their human and mouse counterparts. 相似文献
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107.
Laura Hern��ndez-Terrones Mario Rebolledo-Vieyra Martin Merino-Ibarra Melina Soto Adrien Le-Cossec Emiliano Monroy-R��os 《Water, air, and soil pollution》2011,218(1-4):517-528
The quality of groundwater is threatened in karstic regions with very high population growth, such as the eastern coast of Yucatan. As polluted groundwater flows towards the ocean, coastal ecosystems and coral reefs may also be affected. Pollution and the interaction between the coastal aquifer and the reef lagoon were assessed at a developing area (Puerto Morelos, NE Yucatan Peninsula) within the Mesoamerican Coral Reef System. Coastal environments along the land?Csea gradient (wells, mangroves, beaches, submarine springs, the reef lagoon, and the open sea) were sampled. Silicate and salinity were used as tracers of groundwater and seawater, respectively. Their patterns evidence water flow and mixing among these coastal environments. High nitrate concentrations (268.6 ??M) and coliform bacteria densities indicate groundwater pollution in most of the wells sampled and also in mangroves, beaches, and submarine springs. Phosphorous content peaks (14.2 ??M) in mangroves, where it is likely released due to reducing conditions in the sediments. Nitrogen flux toward the lagoon reef through groundwater discharge is estimated at 2.4 ton N km?1 year?1 and phosphorous at 75 to 217 kg P km?1 year?1. These results provide evidence of the need for more detailed groundwater studies and for the integrated management of aquifers and coastal ecosystems in karstic regions. 相似文献
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109.
On a farm where the ration of cows contained 88.0 g of butyric acid, an experimental group of cows (n = 8), producing milk containing 7.9 mg or more acetone per litre, was studied for 14 days for the effect of a 250 g supplement of sodium acetate to the ration (combined with single i.m. administration of vitamins A, D2 and E) on selected metabolism parameters and on milk production. As distinct from the control group of cows (n = 8) from the same farm which produced milk containing 3.9 mg or less acetone per litre and which were fed without sodium acetone supplements, a tendency of increased alkaemia of the organism was suggested in the experimental cows. This tendency manifested itself during the trial in increased pH values, increased base excess (BE) and standard bicarbonate (SB) in the blood, and in an increase in the pH value and net acido basic secretion in urine. A decrease was recorded in the concentration of the acetone + acetacetic acid sum, the same as beta-hydroxybutyric acid in blood and the sum of acetone and acetacetic acid in milk (P less than 0.01). An insignificant increase of the activity of gammaglutamyl transpeptidase (GMT) was recorded in the blood serum of the experimental cows and a significant increase occurred in the content of potassium (up to P less than 0.01) and urea (up to P less than 0.01) in urine. The supplement of sodium acetate to the feed ration did not influence the degree of ketonuria and the finding of urobilinogen in urine.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
110.
Maisa?B.?Ciampi Eiko?E.?Kuramae Roseli?C.?Fenille Maurício?C.?Meyer Nilton?L.?Souza Paulo?C.?CeresiniEmail author 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(2):183-196
Rhizoctonia solani AG-1 IA causes leaf blight on soybean and rice. Despite the fact that R. solani AG-1 IA is a major pathogen affecting soybean and rice in Brazil and elsewhere in the world, little information is available on its genetic diversity and evolution. This study was an attempt to reveal the origin, and the patterns of movement and amplification of epidemiologically significant genotypes of R. solani AG-1 IA from soybean and rice in Brazil. For inferring intraspecific evolution of R. solani AG-1 IA sampled from soybean and rice, networks of ITS-5.8S rDNA sequencing haplotypes were built using the statistical parsimony algorithm from Clement et al. (2000) Molecular Ecology 9: 1657–1660. Higher haplotype diversity (Nei M 1987, Molecular Evolutionary Genetics Columbia University Press, New york: 512p.) was observed for the Brazilian soybean sample of R. solani AG-1 IA (0.827) in comparison with the rest of the world sample (0.431). Within the south-central American clade (3-2), four haplotypes of R. solani AG-1 IA from Mato Grosso, one from Tocantins, one from Maranhão, and one from Cuba occupied the tips of the network, indicating recent origin. The putative ancestral haplotypes had probably originated either from Mato Grosso or Maranhão States. While 16 distinct haplotypes were found in a sample of 32 soybean isolates of the pathogen, the entire rice sample (n=20) was represented by a single haplotype (haplotype 5), with a worldwide distribution. The results from nested-cladistic analysis indicated restricted gene flow with isolation by distance (or restricted dispersal by distance in nonsexual species) for the south-central American clade (3-2), mainly composed by soybean haplotypes. 相似文献